1. Field of the Invention
The present invention relates to a single chip with multi-LED, in which a plurality of LEDs is integrated, and the plurality of LEDs is connected by a metal wire to form a parallel circuit or a series circuit.
2. Description of the Related Art
An LED is a photoelectric device that actively emits light when electrically powered. Being small, electrically efficient and good for initial driving, LEDs are widely used in general illumination, large billboards, and backlight sources for monitors.
Currently, the important development trend in LEDs is to enhance luminant brightness, which can be achieved by increasing the size of LEDs. A LED provided by the photoelectric industry has an approximately rectangular area with the length of 12 mil to 14 mil. If the length is larger than 30 mil, the LED is called a high-brightness LED chip. The LED chip with a large area can provide a relatively large Ruminant area. However, many problems may be incurred. First, a relatively large luminance area cannot be formed across the entire large area. Current usually passes through a path with the lowest impedance, so in the large area, the light-emitting region with the current passing through is mainly concentrated in certain portions. Moreover, with the increase of the area of the LED, the paths for current passing through increase and the heat generated by the impedance increases greatly. The heat generated by the LED with a large area cannot be dissipated easily, so the working life of the LED is shortened, and the luminant efficiency is reduced.
Another method of achieving high brightness involves packaging a plurality of chips in one package body or one module, so as to replace the single LED chip with a large size. This method is used to mix the chips with different luminant colors to obtain white light or light with a specific color.
For the current LED industry, the multi-chip packaging method has many problems to be solved. First, the precision of the packaging table has a performance limitation, and the distance between the chips cannot be reduced to a minimum, so that it is difficult to reduce the package size. If the distance between the chips is too small, silver paste or solder used for fixing may be extruded, resulting in the LED short-circuiting. Further, the light beams emitted by the LED at different positions easily become scattered light beams after passing through a single lens.
Moreover, since the LED has the characteristics of a diode, i.e., the relation between the driving current and voltage of the diode does not conform to Ohm's Law, it is difficult to change the luminance brightness of the current LED by using the driving voltage. The changing of the brightness of the LED depends on the adjustment of the driving current of the LED, and the curve of the driving current and voltage of the LED is not completely linear. Therefore, in order to adjust the brightness of the LED, it is necessary to use the complex circuit to control current.
In view of the above, the market seeks to solve the problems of the high-brightness LED chip in terms of luminance area utilization rate, heat dissipation, service life, and difficulty in packaging.